For purposes of this disclosure, the term electromagnetic interference (EMI) is understood to refer to electromagnetic emission and radiation that includes both electromagnetic interference and radio-frequency interference (RFI). The term electromagnetic compatibility (EMC) is understood to refer to the ability to combat EMI through the shielding of electronic components which may be affected by EMI.
Certain electronic parts, located primarily on circuits, radiate electromagnetic waves, which can cause noise (i.e., unwanted signals) to appear in other electronic components existing within a certain proximity of the radiating electronic parts. Accordingly, it is common to provide shielding and/or grounding for electronic components that use circuitry that emits electromagnetic radiation or for electronic components that are susceptible to electromagnetic radiation. Such shielding may be grounded to allow the electromagnetic radiation to be dissipated without disrupting the operation of the electronic components.
One method for providing this shielding has been through a stamped metal shield having individual “fingers,” or elongated metal strips, typically made of a stainless steel. Such an EMC shield is also know as a “fingerstock” and is typically placed over an electronic component to reflect or contain EMI emissions. These fingers are formed around the electronic component to reduce undesirable EMI emission and/or effects of electromagnetic radiation. The spacing of each finger depends on the frequencies of the EMI waves. Typically, the higher the frequency that the EMC shield is designed to protect the electronic component from, the smaller the spacing between the fingers. Reducing the space between the fingers may also reduce the amount of unwanted emissions that may pass through the EMC shield from the components.
To reduce the spacing between the fingers, a stamping tool used to manufacture the EMC shield has to be made smaller in order to achieve the smaller gap. As a result, life expectancy of the stamping tool decreases as the gap between the fingers of the EMC shield is made smaller.